How Relevant Is Nutrient Timing?
By Anthony Almada, Muscular Development
Nutrient timing has been embraced like text messaging. If you’re not a texter, you are an ignorant fool or have been mentally hibernating for years (it’s irrelevant to mention that text messaging may be slower than Morse code: http://www.youtube.com/watch?v=AhsSgcsTMd4). Nutrient timing is based upon the premise that providing nutrients— primarily protein and carbohydrate— at a certain time in relation to an exercise bout will lead to greater adaptations to training, compared to getting your nutrition haphazardly. Most believers have been convinced that the ideal time is AFTER a bout of intense training. No doubt, if you follow the timing rules it will, in addition to increasing muscle mass and performance, cure baldness, rip 10 percent of your body fat off like Velcro
If you’re reading this column 1) you likely engage in resistance training, and have been doing so for many months to a few decades, and 2) you are curious enough to see if there’s anything in this column that could enable you to become bigger (muscle-wise), leaner, faster, or stronger, without using surgery or pharmacy. Given that point 1 is a safe bet, would you assume that your veteran resistance-trained body would respond the same to training as that of a person who has never resistance-trained, or who has allowed her/himself to be detrained for months to years, only to start training again? If you were to buy a product that was positioned as Mass & Strength In a Bottle™, would you be more inclined to buy it if it was shown in university studies to 1) boost muscle protein synthesis and clamp down on catabolism after a single intense training session, or 2) produce greater gains in muscle cross-sectional areas and 1-rep max for bench press and squats?
A recent review and position paper by the International Society of Sports Nutrition (ISSN) looked at nutrient timing in relation to exercise performance, glycogen repletion, and training adaptations (body composition, muscle mass, and muscle fiber size).1 One conclusion was that ingesting a carb + protein supplement after training promotes greater increases in strength and more favorable changes in lean mass and fat mass. Pretty compelling statement, eh?
If you’re like some of my friends, you’re as anxious as a penned rodeo bull, bursting out of the gym to your gym bag, locker, or car, to take your post-workout supplement the second you finish your last rep. If I was to walk up to that bullpen, watching your nostrils flare and nasal secretions shooting outward, I’d wipe your nose, cover it with my hand, and then ask, “How many studies have been done in resistance-trained subjects AND where the long-term impact of ‘nutrient timing’ (immediately pre- or post-training OR hours apart from pre- or post training) was assessed?” If you use the ISSN paper to answer the question, only ONE study.2 A sorely-overlooked fact is that most studies involving resistance-training use untrained subjects. That’s the way it is. All of the other studies reviewed either 1) used subjects who were resistance untrained, 2) there was no comparison of timing of nutrients, or 3) it was a short-term study (like one training session) where physique/body comp measures would be pointless.
That lone study took 23 non-competitive, young (early 20s) Australian bodybuilders with an average of three years of experience and matched them for max strength (1 rep max; 1RM). Half of the group then took a carb + protein + creatine monohydrate supplement (40 percent protein from whey protein isolate, 43 percent dextrose, and 7 percent creatine monohydrate) just before and just after training (four personal training supervised sessions in the mid-late afternoon/week for 10 weeks). The other half took the same supplement twice daily on training days (same training regimen as pre-post group), yet before breakfast and before sleep (a.m.-p.m.) on the same training days.
If you accept that the subjects in the a.m.-p.m. group didn’t eat or drink anything for 1-2 hours after they trained— for 10 weeks— then the results for the pre-post group are distinctive: greater lean mass gains and fat mass drops; greater 1RM in squats and bench press; bigger muscle fibers and more contractile protein (not just muscle protein); higher muscle creatine and glycogen content. Again, this is the only study using resistance-trained subjects AND where timing is compared. Admirably, the lead author of the study disclosed that he is a consultant to AST (disclosure is not common— trust me).
Then another study comes out… 30 northeast American college football players (late teens/early 20s), with an average of almost six years of resistance training, and three powerlifters were assigned to either 1) take a liquid protein supplement pre-post, 2) take it in the a.m.-p.m., or 3) take a placebo supplement. All three groups followed a 10-week supervised training regimen (four sessions/week). The liquid protein supplement delivered 42 grams of protein (enzymatically predigested beef collagen, whey protein isolate, casein) and 2 grams of carbs.3 Unlike the prior study, the subjects took the supplement every day during the 10 weeks.
After 10 weeks no significant difference in body comp or any measure of squat or bench press performance was seen between any of the groups, including the placebo group. Modest improvements in strength and power were seen in the two supplemented groups, but they were not significantly greater than the placebo group.
Why the different results between the only two studies done in resistance-trained subjects putting chronic nutrient timing in the hot seat? The first study used bodybuilders who took in about 30 percent more calories (mostly from carbs, not including the supplement), weighed less, and were much leaner. The bodybuilders also were taking in about 10-25 percent more protein at the beginning of the study than the football players. The bodybuilders also supplemented with carbs and creatine monohydrate in addition to protein.
Despite the football players/powerlifters getting the protein supplement every day for 10 weeks, there was no difference. This is not a revelation— more protein does not automatically beget more muscle mass. What may be the revelation is that supplemental calories/carbs may make a difference when protein is at the ceiling of intakes. As it stands, nutrient timing-mediated muscle and strength gains in resistance-trained men is superior for whey protein isolate + dextrose + creatine monohydrate. Any other claim in resistance-trained men has as much proof as non-alcoholic beer.
Anthony Almada (B.Sc., M.Sc.) has worked within the dietary supplement industry since 1975. He has a B.Sc. in physiology and nutritional biochemistry minor from California State University, Long Beach, and an M.Sc. from Berkeley. He has been a co-investigator on over 60 university clinical trials, ranging from arthritis to muscle building and fat loss. Anthony Almada is a member of the executive board of ISSN, and is a fellow of the ISSN.
1. Kerksick C, et al. International society of sports nutrition position stand: nutrient timing. J Int Soc Sports Nutr, 2008;5:17.
2. Cribb PJ, Hayes A: Effects of supplement timing and resistance exercise on skeletal muscle hypertrophy. Med Sci Sports Exerc, 2006;38:1918-25.
3. Hoffman JR, et al. Effect of protein supplement timing on strength, power and body compositional changes in resistance-trained men. Int J Sport Nutr Exerc Metab, (published online advance of print; accessed 13 March 2009).